The invention relates to improvements in apparatus for making smokers' products of the type wherein two or more rod-shaped sections or components are disposed end-to-end and are secured to each other by adherent uniting bands. Typical examples of such smokers' products are filter cigarettes wherein a tobacco-containing rod-shaped section is united with a rod-shaped mouthpiece by a band of tipping paper which is wound around the abutting end portions of the tobacco-containing section and the mouthpiece.
More particularly, the invention relates to improvements in apparatus for making rod-shaped smokers' products, such as filter cigarettes, having a non-circular (normally elliptical) cross-sectional outline. The following description will deal primarily with the making of filter cigarettes; however, it is to be understood that the improved apparatus can be utilized with equal or similar advantage for the making of filter cigarillos, filter cigars and/or other filter tipped rod-shaped smokers' products.
Filter cigarettes having a circular cross-sectional outline are normally produced in so-called filter tipping machines (e.g., in production lines known as PROTOS 2, PROTOS 70, PROTOS 90 and PROTOS 100, all produced and distributed by the assignee of the present application) wherein groups normally containing two coaxial plain cigarettes of unit length and a filter mouthpiece of double unit length between them, and each carrying an adhesive-coated uniting band, are caused to advance through a passage between a drum shaped rolling conveyor and a stationary rolling member. The groups, which are partially confined in axially parallel peripheral flutes of the conveyor, are caused to roll about their respective axes during advancement through the passage whereby the uniting bands are draped around the respective filter mouthpieces of double unit length and the neighboring end portions of the respective plain cigarettes of unit length so that each group is converted into a filter cigarette of double unit length. Such filter cigarettes of double unit length are thereupon severed midway across their convoluted tubular uniting bands to yield pairs of filter cigarettes of unit length. Reference may be had, for example, to commonly owned U.S. Pat. Nos. 4,969,551 and 5,135,008 the disclosures of which should be considered as being incorporated into this specification. Apparatus of the just outlined character are utilized to turn out trillions of round filter cigarettes per annum.
The method of and the apparatus for the making of round filter cigarettes cannot be utilized for the making of filter cigarettes having non-circular (particularly elliptical) cross-sectional outlines. The reason is that an article having a non-circular cross-sectional outline will not roll through a passage or channel between a rigid drum-shaped conveyor and a rigid stationary rolling member. On the other hand, there is a considerable demand for filter cigarettes and other filter tipped rod-shaped smokers' products having an elliptical or other non-circular cross-sectional outline. Heretofore known proposals to mass-produce filter cigarettes having non-circular cross-sectional outlines involve the replacement of the rigid stationary rolling member with a flexible belt or band which is driven in the direction of advancement of groups of axially aligned rod-shaped articles having a non-circular cross-sectional outline and moves at a speed less than the speed of the fluted drum-shaped conveyor which advances groups of articles toward and into the passage. The groups of articles which enter the passage are caused to roll relative to the periphery of the fluted conveyor and relative to the adjacent surface of the belt or band whereby the configuration of the belt or band varies in response to rolling of the groups during advancement through the passage. Reference may be had, for example, to European patent No. 0 124 289 B1 which discloses a machine for the making of filter cigarettes having a non-circular cross-sectional outline by resorting to a fluted rotary drum-shaped conveyor and a flexible belt or band as a means for convoluting the uniting bands around the filter mouthpieces and the adjacent end portions of the respective plain cigarettes. A drawback of the apparatus which is disclosed in the European patent is that the pressure upon the groups which are in the process of rolling through the passage between the rigid drum-shaped conveyor and the yieldable belt or band varies within a wide range during each revolution of the articles. This exerts an adverse influence upon the appearance and/or other desirable characteristics of the thus obtained smokers' products.